import math

AB = float(input())  # 弦长度
CD = float(input())  # 弓高度


R = ((AB/2)**2 + CD**2)/(CD*2)
Haob = 2*math.asin((AB/2)/R)
sector = (Haob/2)*(R**2)
triangle = 1/2*(R**2)*math.sin(Haob)
arch = sector - triangle
a = int(arch/240)
print(f"弓形田地面积为{a}亩零{arch%240:.2f}平方步")